46 lines
1.4 KiB
GLSL
46 lines
1.4 KiB
GLSL
uniform sampler2D u_Tex0;
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varying vec2 v_TexCoord;
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// some const, tweak for best look
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const float sampleDist = 1.0;
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const float sampleStrength = 2.2;
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void main(void)
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{
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// some sample positions
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float samples[10] =
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float[](-0.08,-0.05,-0.03,-0.02,-0.01,0.01,0.02,0.03,0.05,0.08);
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// 0.5,0.5 is the center of the screen
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// so substracting v_TexCoord from it will result in
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// a vector pointing to the middle of the screen
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vec2 dir = 0.5 - v_TexCoord;
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// calculate the distance to the center of the screen
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float dist = sqrt(dir.x*dir.x + dir.y*dir.y);
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// normalize the direction (reuse the distance)
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dir = dir/dist;
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// this is the original colour of this fragment
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// using only this would result in a nonblurred version
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vec4 color = texture2D(u_Tex0,v_TexCoord);
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vec4 sum = color;
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// take 10 additional blur samples in the direction towards
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// the center of the screen
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for(int i = 0; i < 10; i++)
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sum += texture2D(u_Tex0, v_TexCoord + dir * samples[i] * sampleDist);
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// we have taken eleven samples
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sum *= 1.0/11.0;
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// weighten the blur effect with the distance to the
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// center of the screen ( further out is blurred more)
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float t = dist * sampleStrength;
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t = clamp(t ,0.0,1.0); //0 <= t <= 1
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//Blend the original color with the averaged pixels
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gl_FragColor = mix(color, sum, t);
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} |